Automated machinery for fabricating a wrought-iron fence

ABSTRACT

Automated method and machinery for fabricating a wrought-iron fence panel. The machinery includes (a) automated programmable machinery for welding vertical pickets to horizontal runners to form a fence panel; (b) automated programmable machinery for straightening the fence panel; (c) automated programmable machinery for washing the fence panel; (d) automated programmable machinery for drying the fence panel; (e) automated programmable machinery for painting the fence panel; and (f) automated programmable conveyor machinery for conveying the vertical pickets, the horizontal runners, and the fence panel from station to station.

BACKGROUND OF THE INVENTION

This application is a continuation-in-part of application Ser. No.08/975,986, now U.S. Pat. No. 5,971,365, filed Nov. 21, 1997.

The present invention relates to fence construction. More particularly,the invention relates to an automated process for fabricatingwrought-iron fences.

SUMMARY OF THE INVENTION

In general, the present invention in a first aspect provides anautomated method for fabricating components of a wrought-iron fence. Themethod comprises the steps of (a) providing a plurality of horizontalrunners and a plurality of vertical pickets; (b) automatedly welding thevertical pickets to the horizontal runners to form a fence panel; (c)automatedly transferring the fence panel to a table run-out conveyorwhich includes a set of chains with a pickup block on each chain; (d)utilizing the table run-out conveyor to automatedly transfer the fencepanel to a conveyor loading station which includes a hydraulic-drivenunit with pickup hooks capable of conveying the fence panel; (e)utilizing the hydraulic-driven unit to automatedly transfer the fencepanel to an overhead conveyor line; (f) utilizing the overhead conveyorline to automatedly transfer the fence panel to a fence sectionstraightener; (g) utilizing the fence section straightener toautomatedly straighten the fence panel; (h) utilizing the overheadconveyor line to automatedly transfer the straightened fence panel to awash tank; (i) utilizing the wash tank to automatedly wash the fencepanel; (j) utilizing the overhead conveyor line to automatedly transferthe washed fence panel to a drying station; (k) utilizing the dryingstation to automatedly air-dry the washed fence panel; (l) utilizing theoverhead conveyor line to automatedly transfer the dried fence panel toa paint tank; and (m) utilizing the paint tank to automatedly paint thefence panel.

In a second aspect the invention provides automated machinery forfabricating components of a wrought-iron fence from a plurality ofhorizontal runners and vertical pickets. The machinery comprises: (a)automated programmable means for welding the vertical pickets to thehorizontal runners to form a fence panel; (b) automated programmablemeans for straightening the fence panel; (c) automated programmablemeans for washing the fence panel; (d) automated programmable means fordrying the fence panel; (e) automated programmable means for paintingthe fence panel; (f) automated programmable conveyor means for conveyingthe fence panel from the welding means to the fence-straightening means;(g) automated programmable conveyor means for conveying the fence panelfrom the fence-straightening means to the washing means; (h) automatedprogrammable conveyor means for conveying the fence panel from thewashing means to the drying means; and (i) automated programmableconveyor means for conveying the fence panel from the drying means tothe painting means.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic representation of an automated welding machinemade in accordance with the principles of the present invention.

FIG. 2 is a schematic representation of an automated table run-outconveyor and an automated conveyor load station, made in accordance withthe principles of the present invention.

FIG. 3 is a schematic representation of an automated fence sectionstraightener made in accordance with the principles of the presentinvention.

FIG. 4 is a schematic representation of an automated wash tank made inaccordance with the principles of the present invention.

FIG. 5 is a schematic representation of automated machinery for drying afence panel, made in accordance with the principles of the presentinvention.

FIG. 6 is a schematic representation of automated machinery for paintinga fence panel, made in accordance with the principles of the presentinvention.

FIG. 7 is a schematic representation of an automated conveyor systemmade in accordance with the principles of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

More specificially, reference is made to FIG. 1, in which is shown anautomated welding machine, made in accordance with the principles of thepresent invention, and generally designated by the numeral 2.

The automated welding machine 2 comprises a programmable, movablecarriage 4; programmable pneumatic means 14 for automatedly clampinghorizontal runners 3 to vertical pickets 5 in a perpendicularconfiguration on the movable carriage 4, by clamps 6 automatedly poweredand operated by automated pneumatic means 14; a hydraulic cylinder 12,for forward and reverse movement of the carriage 4; a plurality ofprogrammable welding guns 8, for welding the horizontal runners 3 to thevertical pickets 5, to form a fence panel 7; and a programmablephotocell switch 10a for a hydraulic feed-speed control valve 11,indexing the movable carriage 4 to move at a slower speed during thewelding operation, and at a faster speed for conveying the clampedhorizontal runners 3 and vertical pickets 5 to and under the weldingguns 8 for welding, and away from the welding guns 8 after the verticalpickets 5 have been welded to the horizontal runners 3.

The horizontal runners 3 and the vertical pickets 5 are manually loadedonto the movable carriage 4 with panel fixture. An operator then startsthe automated welding machine 2, which pneumatically clamps the verticalpickets 5 to the horizontal runners 3, and automatedly indexes thecarriage 4 for the faster and slower speeds.

Reference is now made to FIG. 7, in which is shown an automated conveyorsystem, made in accordance with the principles of the present invention,and generally denoted by the numeral 70. The automated conveyor system70 comprises a plurality of hydraulic power units 18; an overhead cable22; a pulley 24; a plurality of limit switches 10; a plurality of timers64; a plurality of chain-and-sprocket units 16; and a plurality of hooks26.

Reference is again made to FIG. 1.

After the operator pushes a start switch 9, the carriage 4 will "rapidtravel" to the first picket 5 to be welded. At this point the photocellswitch 10a will switch the hydraulic feed-speed control valve 11 from"rapid travel" to "feed speed." After the picket 5 has been welded tothe runner 3, the photocell switch 10a will then switch to "rapidtravel" for the next picket 5 to be welded.

After the last picket 5 has been welded, the carriage 4 will "rapidtravel" forward to the end of the stroke of the hydraulic cylinder 12.An elevator 13 controlled by a limit switch 10 will then lift the weldedfence panel 7 from the movable carriage 4. When the elevator 13 is in"full up" position, the carriage 4 will return to the start position. Atthe same time the conveyor system 70 will move the fence panel 7 awayfrom the welding machine 2, using the overhead cable 22, a pulley 24,and hooks 26.

The automated welding machine 2 further comprises a base 15 on which themovable carriage 4 is mounted. The base 15 has an inverted "VI" rail 17and a "flat" rail 19 to channel the carriage 4 for forward and reversemotion. The hydraulic cylinder 12 raises and lowers the elevator 13. Thecarriage 4 has two "flat wheels" and two "V-groove wheels." Thehydraulic cylinder 12, which preferably has aone-hundred-and-forty-four-inch stroke, is mounted on the carriage 4,with its rod end anchored to the base 15. The hydraulic power unit 18,which is preferably a three-horsepower unit, is rigidly mounted to thebase 15. The output of the hydraulic power unit 18 is preferably aboutthree and one-half gallons per minute at a pressure of approximatelyfive hundred pounds per square inch gauge. An overhead gantry 21 ismounted on the base 15. The gantry 21 has mounted thereon six weldingguns 8 and a "T" bar rail 23. On the bar rail 23 are mounted sixwelding-torch dove-tail slides, with torch holders and torches. Screwhandles allow torch adjustment in and out as well as up and down. Thetorches are preferably set up at approximately a forty-five-degreeangle. Flexible cables run from the welder units to torchesapproximately forty-eight inches long. Elevator 13 lift is accomplishedby arms with a rocker movement and the hydraulic cylinder 12. A secondgantry is mounted on the base 15 forward of the welding torches. To thesecond gantry is mounted an adjustable air-powered hold-down guide andclamps, to navigate each horizontal runner 3 to its correct spacing andposition. A guide of brass sidewalls with a roller hold-down appliespressure on the horizontal runner 3 to keep it tight on the picket 5during welding. Small air cylinders apply the downward pressure to thefront of the runner 3, to hold the runner in position. The small aircylinders are activated when the carriage 4 moves forward from the startposition. Along with the small air cylinder a set of air-cylinder clampsaid in applying downward pressure to the rear of the runner 3. Theair-cylinder clamps are activated by forward motion of the carriage 4and by an air valve (not shown), and are retracted at the end of thewelding cycle.

Reference is now made to FIG. 2, in which is shown an automated tablerunout conveyor 28 and an automated conveyor loading station 29, made inaccordance with the principles of the present invention, the combinationbeing generally designated by the numeral 20.

After the fence panel 7 has been moved down line of the welding machine2 by the automated conveyor system 70 (FIG. 7), the automated conveyorloading station 29 picks up and hangs the fence panel 7 on the overheadcable 22.

The automated table run-out conveyor 28 comprises a set of chains (notshown) with a pickup block (not shown) on each chain. The pickup blocksare mounted on a special link, which allows normal functioning of thechain while conveying the panel 7 via the attached pickup blocks. Theconveyor 28 is started and stopped by two limit switches 10. When theelevator 13 (FIG. 1) is in "full up" position--its highest point--alimit switch 10 activates the conveyor 28 to move the panel 7 from thewelding machine 2 (FIG. 1) to the conveyor loading station 29.

At the conveyor loading station 29, the drive blocks drop away and thepanel 7 stops moving. Thereafter a limit switch 10 activates and startsthe conveyor loading station 29. The pickup blocks move to the pickupposition for another panel 7, where they are stopped by a limit switch10.

The conveyor loading station 29 is an hydraulic-driven 12, 18 unit withpickup hooks 26 for transporting a fence panel 7 from the table run-outconveyor 28 to the overhead cable 22 shown in FIG. 7. The pickup hooks26 are controlled both vertically and horizontally. The conveyor loadingstation 29 is activated by a limit switch 10 off the table run-outconveyor 28 when the panel 7 is in position for pickup. The firstmovement is vertical. The pickup hooks 26 lift the fence panel 7 off thetable run-out conveyor 28 to a height which clears the conveyor 28. Thesame set of pickup hooks 26 then carry the panel 7 horizontally towardthe overhead cable 22. The pickup hooks 26 carry the panel 7 over asecond set of staggered pickup hooks 26 attached to the overhead cable22, thereby fully extending the hooks 26, activating a limit switch 10,and moving the fence panel 7 downward in a second vertical movement. Theresult is the setting of the panel 7 on the overhead cable 22 in thesecond set of staggered hooks 26, to drain the paint from the horizontalrunners 3. A one-way limit switch (not shown) then activates ahorizontal and vertical retraction of the hooks 26 in a retracting glideslope, thereby returning the hooks 26 to their original start position.The pickup hooks 26 are now ready to transport another fence panel 7.The conveyor loading station 29 includes a vertical roller slide 29a anda horizontal roller slide 29b for transporting the fence panels 7 viathe pickup hooks 26.

Reference is now made to FIG. 3, in which is shown an automated fencesection straightener, made in accordance with the principles of thepresent invention, and generally designated by the numeral 30.

The fence section straightener 30 comprises a press member 32, a rigidbackstop 34, a pair of hydraulic cylinders 12 to force a fence panel 7against the backstop 34, and limit switches 10 which control theposition of the press member 32.

The fence panel 7, which has been automatedly transferred via the cable22 and the hooks 26 from the conveyor loading station 29 to theautomated fence section straightener 30, is disposed between the pressmember 32 and the backstop 34.

When the fence panel 7 is "delivered" from the conveyor loading station29 and disposed between the press member 32 and the backstop 34, a limitswitch 10 at the run-out table conveyor 28 (FIGS. 1 and 2) activates thehydraulic cylinders 18, which automatedly and in unison urge the pressmember 32 and fence panel 7 toward and against the backstop 34, therebystraightening the fence panel 7; and automatedly and in unison releasethe straightened fence panel 7. The limit switch 10 which controls thepressing operation is the same limit switch used to start theconveyor-loading cycle. After the fence panel 7 has been pressedstraight, a second limit switch (not shown) is automatedly activated toretract the press member 32 and thereby complete the press cycle.

The press member 32 has an adjustable press stroke to preventovercorrection or overbending of the fence panel 7.

Reference is now made to FIG. 4, in which is shown a programmable,self-contained, pressurized wash tank 40 which includes a plurality ofrotatable wash arms 42 equipped with high-pressure spray nozzles 42a.The rotatable wash arms 42 are turned via a chain-and-sprocket unit 16by an electric motor 44, and eject a pressurized spray 46 at and towarda fence panel 7. The spray comprises a mixture of heated degreasingsolution and water.

The washing station (not shown) is a metal enclosure with an opening ateach end. The openings allow the overhead cable 22, the hooks 26, andthe fence panels 7 to pass freely therethrough.

The spray nozzles 42a are usually set at a forty-five degree angle withrespect to the fence panel 7. This angle enables washing all sides andparts of the fence panel 7. A pressure-washing pump (not shown) with agas or electric heat source (not shown) controls the temperature of thewash mixture at approximately 190° F.

The fence panel 7 is transported to and disposed within the pressurizedwash tank 40 by means of the overhead cable 22 and hooks 26. Limitswitches 10 stop movement of the cable 22 to position and dispose thefence panel 7 within the pressurized wash tank 40. The same limitswitches 10 restart movement of the cable 22 to convey the fence panelfrom the wash tank 40.

Reference is now made to FIG. 5, in which is shown automated machinery50 for drying a fence panel 7. The automated drying machinery 50comprises a pair of programmable air blowers 52 which force compressedair through pipe ducts 54 to air knives 54a. The automated dryingmachinery 50 is disposed in a programmable drying station (not shown).

A fence panel 7 is transported from the washing station (not shown) andautomated wash tank 40 (shown in FIG. 4) to the automated dryingmachinery 50 and programmable drying station (not shown), using pickuphooks 26 suspended from the overhead cable 22. The fence panel 7 isautomatedly passed between juxtaposed, parallel, spaced-apart pipe ducts54 while air is blown therethrough. The air knives 54a at the distalends of the ducts 54 increase the pressure of the air, in order to blowexcess wash solution from the fence panel 7. The blowers 52 arepreferably centrifugal blowers. The air knives 54a are beneficially setat about a forty-five-degree angle with respect to the fence panel 7 forthe most efficient drying of the fence panel 7. The drying station workscontinuously as the fence panel 7 is conveyed therethrough.

Reference is now made to FIG. 6, in which is shown automated machinery60 for painting a fence panel 7. Hydraulic cylinders 12 automatedly lifta paint tank 62 vertically to submerge therein a stationary fence panel7 suspended from hooks 26 supported by the overhead cable 22.Programmable timers 64 and limit switches 10 allow a delay of theconveyor system 70 (FIG. 7) sufficient to paint the fence panel 7 and todrain excess paint back into the tank 62 after the tank 62 has beenautomatedly lowered and returned to its starting position.

The paint dip-tank station (not shown) is driven by a hydraulic powerunit 18 with a pair of hydraulic cylinders 12 and a vertical slide (notshown). The dip-paint tank 62 is mounted on the vertical slide.

The start cycle for the dipping operation is activated by a relay (notshown) with a start switch (not shown) disposed at the site of theautomated welding machine 2 (FIG. 1). A limit switch 10 mounted overheadensures proper positioning of the panel 7. Another limit switch 10 atthe top of the cycle will return the tank 62 to its starting position.

The paint-dip station (not shown) includes a filtration unit 64 tofilter out paint contaminants such as soil, metal shavings, etc.

Reference is again made to FIG. 7.

The automated conveyor system 70 is a continuous cable-driven systeminstalled on the outer perimeter of the floor-plan site (not shown). Ahydraulic motor 18a in a hydraulic power unit 18 drives the overheadcable 22 at a variable speed using a gear-reduction unit (not shown).The cable 22 has one long and one short hook (not shown) to horizontally"stagger" a fence panel 7 being suspended therefrom. The conveyor system70 transports the runners 3, pickets 5, and panels 7 (FIG. 1) throughthe entire fabrication process, then makes a loop to return the pickuphooks 26 to the vicinity of the automated welding machine 2.

The conveyor system 70 and the cable 22 are not limited to straight,linear motion. The cable 22 is capable of turning a corner equal toone-hundred and eighty degrees. A take-up station (not shown) keeps thecable 22 taut.

The conveyor system 70 is operable in both manual and automatic modes.In the preferred automatic mode, a cycle is started by a start switch(not shown) proximate the automated welding machine 2 (FIG. 1), and isstopped by a limit switch 10 proximate the dip-paint tank 62 (FIG. 6).In the manual mode it can be started and stopped at any point in thecycle.

What is claimed is:
 1. Automated machinery for fabricating components ofa wrought-iron fence from a plurality of horizontal runners and verticalpickets, the machinery comprising:(a) automated programmable means forwelding the vertical pickets to the horizontal runners to form a fencepanel; (b) automated programmable means for straightening the fencepanel; (c) automated programmable means for washing the fence panel; (d)automated programmable means for drying the fence panel; (e) automatedprogrammable means for painting the fence panel; (f) automatedprogrammable conveyor means for conveying the fence panel from thewelding means to the fence-straightening means; (g) automatedprogrammable conveyor means for conveying the fence panel from thefence-straightening means to the washing means; (h) automatedprogrammable conveyor means for conveying the fence panel from thewashing means to the drying means; and (i) automated programmableconveyor means for conveying the fence panel from the drying means tothe painting means.
 2. The automated machinery of claim 1, wherein themeans for welding the vertical pickets to the horizontal runnersinclude:(j) automated programmable pneumatic means for clamping thehorizontal runners and vertical pickets to one another on a movablecarriage in a disposition for welding the vertical pickets to thehorizontal runners in a perpendicular configuration; and (k) automatedprogrammable means for indexing the carriage with a slower speed forwhile welding is in progress, and a faster speed for conveying theclamped horizontal runners and vertical pickets to and under a pluralityof welding guns for welding, and away from the welding guns after thevertical pickets have been welded to the horizontal runners.
 3. Theautomated machinery of claim 1, wherein the means for welding thevertical pickets to the horizontal runners include:(j) a programmable,movable carriage; (k) programmable means for clamping the verticalpickets to the horizontal runners in a perpendicular configuration onthe movable carriage; (l) a plurality of programmable welding guns, forwelding the horizontal runners and the vertical pickets to one anotherin a perpendicular configuration; and (m) means for programming themovable carriage to move at a slower speed for while welding is inprogress, and at a faster speed for conveying the clamped horizontalrunners and vertical pickets to and under the welding guns for welding,and away from the welding guns after the vertical pickets have beenwelded to the horizontal runners.
 4. The automated machinery of claim 1,wherein the means for straightening the fence panel include:(j) aplurality of programmable limit switches, to stop movement of a conveyorline; (k) a plurality of programmable hydraulic cylinders, forautomatedly and in unison urging the fence panel against a rigidbackstop, thereby automatedly straightening the fence panel, and forautomatedly and in unison releasing the straightened fence panel.
 5. Theautomated machinery of claim 1, wherein the means for straightening thefence panel include:(j) a rigid backstop; (k) a plurality ofprogrammable hydraulic cylinders, for automatedly and in unison urgingthe fence panel against the backstop, thereby automatedly straighteningthe fence panel, and for automatedly and in unison releasing thestraightened fence panel and (l) a plurality of programmable limitswitches, for stopping movement of the conveyor means while the fencepanel is being straightened, and for restarting movement of the conveyormeans after the fence panel has been straightened.
 6. The automatedmachinery of claim 1, wherein the means for washing the fence panelinclude:(j) a plurality of programmable limit switches, for automatedlystopping movement of the conveyor means and disposing the fence panelwithin a programmable self-contained, pressurized wash tank whichincludes a plurality of rotatable wash arms equipped with high-pressurespray nozzles; and (k) programmable automated means for rotating thewash arms while ejecting a pressurized spray comprising a mixture ofheated degreasing solution and water toward the fence panel.
 7. Theautomated machinery of claim 1, wherein the means for washing the fencepanel include:(j) a programmable, self-contained, pressurized wash tankwhich includes a plurality of rotatable wash arms equipped withhigh-pressure spray nozzles; (k) a plurality of programmable limitswitches, for stopping movement of the conveyor means and disposing thefence panel within the wash tank for washing the fence panel, and forrestarting movement of the conveyor means after the fence panel has beenwashed; and (l) automated means for rotating the wash arms whileejecting a pressurized spray comprising a mixture of heated degreasingsolution and water at and toward the fence panel, thereby automatedlywashing the fence panel.
 8. The automated machinery of claim 1, whereinthe means for drying the fence panel include:(j) a pair of automatedblowers constructed and arranged to air-dry the washed fence panel bypassing the fence panel between the blowers; (k) a plurality of ductsfor conveying pressurized air from the blowers; and (l) an air knife atthe distal end of each duct, for increasing the pressure of air passingtherethrough, thereby increasing the efficiency of drying the fencepanel and blowing excess liquid from the fence panel.
 9. The automatedmachinery of claim 1, wherein the means for drying the fence panelinclude:(j) a pair of automated blowers; (k) means for programmingmovement effecting passage of the washed fence panel between theblowers; (l) means for programming the blowers to discharge air from theblowers to and against the surface of the fence panel while the fencepanel is being passed between the blowers; (m) a plurality of ducts forconveying pressurized air from the blowers; and (n) an air knife at thedistal end of each duct, for increasing the pressure of air passingtherethrough, thereby increasing the efficiency of drying the fencepanel and blowing excess liquid from the fence panel.
 10. The automatedmachinery of claim 1, wherein the means for painting the fence panelinclude:(j) an overhead conveyor line; (l) a plurality of automatedhydraulic cylinders for lifting a tank containing paint to a level inwhich a stationary fence panel suspended from the overhead conveyor lineis immersed in the paint, and for lowering the tank to its originalposition; and (l) a plurality of programmable timers and limit switchesconstructed, arranged, and programmed to effect a predetermined delay inthe movement of the overhead conveyor line, for painting the fence paneland for draining excess paint from the fence panel to the tank.
 11. Theautomated machinery of claim 1, wherein the means for painting the fencepanel include:(j) a dip-paint tank; (k) an overhead conveyor line; (l) aplurality of programmable timers and limit switches, for effecting apredetermined temporary stoppage of movement of the overhead conveyorline, to immobilize a fence panel suspended therefrom for a period oftime sufficient to dip the fence panel in the dip-paint tank, and todrain excess paint from the fence panel; and (m) a plurality ofprogrammable hydraulic cylinders constructed, arranged, and programmedto automatedly and vertically lift the dip-paint tank to a level atwhich the suspended fence panel is submerged in the dip-paint tank, andto thereafter return and restore the dip-paint tank to its originaldisposition.
 12. The automated machinery of claim 1, wherein theautomated conveyor means include:(j) an overhead conveyor line; and (k)a plurality of programmable timers and limit switches, for controllingthe movement of the overhead conveyor line in accordance with timingneeds and constraints required to automatedly weld, straighten, wash,dry, and paint a fence panel.
 13. The automated machinery of claim 1,wherein the automated conveyor means include:(j) an overhead conveyorline; (k) a plurality of hydraulic power units, for powering andoperating the overhead conveyor line; and (l) a plurality ofprogrammable timers and limit switches, for controlling the hydraulicpower units by imposing thereon a predetermined schedule, pattern, andsequence of movement of the overhead conveyor line in accordance withtiming needs and constraints required to automatedly weld, straighten,wash, dry, and paint a fence panel.